Method of distributing small scale pyrolysis for production of renewable fuels from waste

ABSTRACT

The present document describes a method and a system of distributing pyrolysis by-products comprising the step of producing pyrolysis by-products produced by small scale pyrolysis of waste at a production site to a by-product processor. The by-product processor may be the production site itself.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority of U.S. provisional patent application 61/867,580 filed Aug. 19, 2013, the specification of which is hereby incorporated by reference.

BACKGROUND

(a) Field

The subject matter disclosed generally relates to a method of producing renewable fuels from waste by distributing small scale waste conversion machines. Specifically, the method includes distributing small scale machines performing a de-polymerization of waste through pyrolysis or gasification that will convert waste produced locally into valuable and energetic by-products that can be either used directly or further processed for production of renewable fuels. The by-products include a gas, a liquid and a solid.

(b) Related Prior Art

The scarcity of economically-viable crude oil has prompted chemical corporations to look for alternative sources of carbon and hydrogen to produce chemicals, biologics and other products. However, biomass is expensive and puts pressure on other food crops by the extensive use of land for energetic purposes. Waste matter becomes one of the foremost raw materials to develop for the production of renewable energy.

In Canada only, a tremendous amount of waste is produced: 25 million tons (an average of 0.8 ton per capita), of which only 25% is diverted. The remaining 17 million tons per year is either incinerated or buried. In the province of Quebec, the average annual rate of waste production is 1.69 tons per year per capita, for which 0.81 ton per year per capita is going straight to elimination and 0.88 ton per year per capita is recycled. These statistics are slightly above the Intergovernmental Panel on Climate Change (IPCC) North-American average where municipal solid waste (MSW) generation rate is 0.65 and 0.49 tons per year per capita for 1996 and 2000 respectively. The numbers proposed by the IPCC report seems a little far compared to the Quebec numbers which mostly matches the statistics of the USA with 1.14 tons per year per capita of MSW generation. According to Canadian average from IPCC, 71% of the MSW is being disposed, 4% incinerated and 19% composted.

The Biomass R&D Technical Advisory Committee to the US Congress stated a goal of replacing 30% of the US petroleum consumption with biofuel by year 2030. On a shorter timescale, the US goal is to supply 35 billion gallons a year of renewable and alternative fuels by 2017. For illustration purposes, according to the US department of energy, the US transportation sector only consumed 30 billion gallons of diesel and 100 billion gallons of motor gasoline and 16 billion gallon of Jet Fuel in 2010. This represents a tremendous opportunity for the bio-oil utilization.

In the last decade, in Canada the waste management costs per capita increased by 72% between 2000 and 2008 mostly due to an increase in collection and transportation costs of waste per capita (67% increase between 2000 and 2008 with an average yearly increase of 7%-8%). Total government expenditures related to the collection and transportation of wastes only in Canada for 2008 was 1.1 G$, which accounts for 42% of the total expenditures for waste management. For the same year, total government expenditures related to operation of disposal facilities reached 465 M$ for a total expenditure of 2.6 G$. By reducing the volume of waste at the source by at least 90% and valorizing the waste by producing valuable by-products, the present invention will target about 60%-70% of the current costs of waste management, create value from a low-value stream and trigger the development of a high-technology industry that develops, collects, transforms and valorizes the waste by-products.

The current waste management approach used in North America is essentially based on door to door collection (single or multi-way collect). Waste is mostly sent to landfills (95% of the waste) and incineration. This approach creates several problems: a) significant costs to municipalities to transport the waste and manage the landfills and incinerators; b) the pollution and nuisance from gaseous and particulate contaminants (decomposition and incineration) and contamination of landfills; c) environmental costs from waste collection: waste collection and transportation entails the combustion of 7 to 15 litres of diesel per ton of waste. Therefore, in the current context, waste is clearly synonym of net expenses: waste is a nuisance that does not contribute to value creation.

This volume of waste is seen as an interesting deposit to feed a new waste conversion system and solve inherent problems related to the current approach of waste management and contribute to the production of renewable fuels.

The cost of conventional biomass (forestry residues, corn stover, crop hulls, etc) is strongly correlated with the cost of the oil barrel due to its mechanical requirements (seeding, harvesting and transportation). From that perspective, MSW constitutes a cheap and year-round easily accessible feedstock that competes strongly against conventional biomass.

Current technologies for advanced conversion of waste into liquid fuel energy include pyrolysis and gasification followed by synthesis.

Pyrolysis/gasification of MSW with conventional technology has shown to be hazardous at large scale (10 tons/day and more) due to scale-up difficulties and long term operation problems and especially problems related to heat transfer. For example, wastes pyrolysis with externally heated rotary furnace has suffered serious operation problems due to crusting.

Pyrolysis and gasification of homogeneous feedstock such as scrap tires, straw, wood chips and corn stovers have shown to be working at large scale because the composition is constant over time. There is still a strong research and development effort required before the technology can be scaled up to reach profitability.

In fact, scale-up of these technologies are a real challenge which makes their operation difficult and long term profitability debatable.

In order to promote production of liquid fuels from MSW, fast pyrolysis is preferred by means of fast heating the MSW. Conventional processes using wall heating (heat transfer by convection and conduction) to provide heat to the reaction are not fast enough to favour production of oil.

For that reason, much interest is given to microwave heating as the most rapid way of achieving fast pyrolysis.

Microwave heating, although not sensitive to fouling compared to other conventional heating approaches, can hardly be applied to large scale units because of the issue with distributing the microwaves in a larger enclosure. It is also more selective towards specific molecules which yield better quality liquid products. However, it works well at small and medium scale.

Large pyrolysis/gasification plants are centralized and require additional costs to carry the required large flow of feedstock required to run the plant: it then has a negative impact on the environment and profitability of the current business because it adds an additional cost to the feedstock. In fact, biomass and raw MSW have low density which makes larger volumes to carry the feedstock to the central conversion facility.

In contrast, the proposed small distributed pyrolysis/gasification approach disclosed herein proposes to convert the waste at the production site and produce dense by-products (liquid oil and solid char powder) which reduce the volume of by-products to be collected and transported. Moreover, the fraction of original MSW that was converted in gas can be used at site for heating, water heating or cooking and further reduce the mass of by-products to be transported and decreases furthermore the overall collection and transportation cost of waste after its conversion at site.

The scale-up of the proposed approach involves adding more individual machines to increase production rate. It then significantly reduces the research and development effort required to match the desired production rate.

Therefore, there is a need for methods for transforming wastes into useful fuel by-products.

Also, there is a need for methods for transforming wastes into useful by-products and reducing the volume of waste produced.

Also, there is a need for methods of reducing the cost of waste management, pollution due to transportation and risks associated with the scale-up of conventional technologies.

SUMMARY

According to an embodiment, there is provided a method of performing small scale pyrolysis in a distributed way and creating value through at least one pyrolysis by-product produced therefrom which comprises:

-   -   a) producing at least one pyrolysis by-product by small scale         pyrolysis of at least one waste at a production site to be used         by at least one by-product processor.

The method may further comprise the step a′) prior to step a):

-   -   a′) operating an apparatus for small scale pyrolysis of the         waste at a production site.

The method may further comprise step b) after step a):

-   -   b) collecting the at least one pyrolysis by-product from the         production sites.

The by-product processor may be at the production site.

The apparatus for small scale pyrolysis may be leased to the production site, sold to the production site, in consignment at the production site, or transported to the production site.

The at least one pyrolysis by-product may be received by an integrator prior to distribution to the at least one by-product processor.

In the method of the present invention, wherein a glass residue, a metal residue, or both produced by the small scale pyrolysis of at least one waste may be recycled.

The operating the apparatus for small scale pyrolysis may be performed by at least one of an owner of the production site, an owner of the apparatus, a producer of the apparatus, a purchaser of the apparatus, the by-product processor, the integrator, a third party operator of the apparatus, a lender of the apparatus, a seller of the apparatus, a leaser of the apparatus, a leaseholder of the apparatus, a transporter of the apparatus, or combinations thereof.

The apparatus for small scale pyrolysis may be a portable apparatus.

The at least one pyrolysis by-product may be chosen from a bio-char, a bio-gas, a bio-oil, and combinations thereof.

The method may further comprise the step of using the bio-gas, the bio-oil and/or the bio-char on-site at the production site.

The bio-gas may be used for heating, water heating, or cooking.

The bio-gas may be used at the production site.

The bio-gas may be mixed with at least one other source of gas.

The bio-gas may be used by at least one of the owner of the production site, the owner of the apparatus, the producer of the apparatus, the purchaser of the apparatus, the by-product processor, the integrator, the third party operator of the apparatus, the lender of the apparatus, the seller of the apparatus, the leaser of the apparatus, the leaseholder of the apparatus, the transporter of the apparatus, or combinations thereof.

The collecting of the at least one pyrolysis by-product may be performed on-demand.

The collecting of the at least one pyrolysis by-product may be performed according to a predetermined schedule.

The collecting of the at least one pyrolysis by-product may be performed according to a level of the pyrolysis by-products at the production site.

The pyrolysis apparatus may further comprise a monitoring system to provide a status of the pyrolysis apparatus.

The status may comprise at least one of an apparatus malfunction, a maintenance requirement, and a by-product level status.

The pyrolysis apparatus may be provided with an encryption key.

The encryption key may be to authorize operation of the pyrolysis apparatus at the production site.

The pyrolysis may be a fast pyrolysis.

The pyrolysis may be a microwave pyrolysis.

The pyrolysis may further include a torrefaction step for removing water from the at least one waste.

The method may further comprise the step of upgrading the bio-oil.

The upgrading may be performed at the production sites, by the integrator, by the by-product processor, or combinations thereof.

The method may further comprise the step of purifying the bio-char.

The step of purifying the bio-char may include removal of metals, homogenization and sterilization, activation of carbon, and combinations thereof.

The by-product processor may be chosen from a energy company, an oil company, a gasoline company, a gas company, a construction material company, an agricultural company or combinations thereof.

The production site may be a house, a restaurant, an office building, a hotel, an airport, a waste treatment plant of an airline, a recycler's site, a sorting facility, and a recycling material drop-off.

According to another embodiment, there is provided a system for performing small scale pyrolysis in a distributed way and creating value through at least one pyrolysis by-product produced therefrom which comprises:

-   -   a pyrolysis apparatus for small scale pyrolysis of at least one         waste at a production site, and     -   a transport apparatus for transportation of the at least one         pyrolysis by-product to at least one by-product processor.

The transport apparatus may be at least one of a motorized vehicle, a piping, or combinations thereof.

The apparatus for small scale pyrolysis may be leased to the production site, sold to the production site, in consignment at the production site, or transported to the production site.

The by-product processor may be at the production site.

The system may further comprise an integrator for receiving the at least one by-product prior to transportation to the by-product processor.

The apparatus for small scale pyrolysis may be a portable apparatus.

The system may further comprise a monitoring system to provide a status of the pyrolysis apparatus.

The status may comprise at least one of an apparatus malfunction, a maintenance requirement, a by-product level status, an authorized operation status and combinations thereof.

The pyrolysis apparatus may be provided with an encryption key.

The encryption key may be to authorize operation of the pyrolysis apparatus at the production site.

The by-product processor may be chosen from a energy company, an oil company, a gasoline company, a gas company, a construction material company, an agricultural company or combinations thereof.

The production site may be a house, a restaurant, an office building, a hotel, an airport, a waste treatment plant of an airline, a recycler's site, a sorting facility, and a recycling material drop-off.

The following terms are defined below.

The term “by-product” is intended to mean a secondary product that is made during the thermal depolymerization of waste by the pyrolysis reaction. Examples of by-products include bio-char, bio-oil, and bio-gas.

The term “integrator” is intended to mean an entity, such as a company that may for example distribute pyrolysis apparatuses, organize and manage collection of the produced by-products and organizes and manages the sale, valorization and/or distribution of by-products to other entities (for example the processors). The integrator may also be comprised of human operated and/or automated machinery which receives the collected by-products and organizes and manages the sale, valorization and/or distribution of by-products to other entities (for example the processors).

The term “processor” is intended to mean an entity, such as a company which receives the by-product and which may use in their own products and/or resell them to others. The processor may also be the production site itself, in situations where the pyrolysis some of the by-products are reused directly by the production site for their own activities.

The term “production site” is intended to mean a site which produces wastes or recyclable matter that are pyrolyzed and produces by-products. Examples of such production sites include houses, restaurants, office buildings, and hotels. Other examples include the waste treatment plant of commercial airlines, as well as airports, which count amongst the largest MSW producer in the world. Other examples include sorting facilities, recycler's collection site, commercial and industrial sites. Thus, the production site may include at least one of a house, a restaurant, an office building, a hotel, an airport, a waste treatment plant of an airline, a recycler's site, a sorting facility, a recycling material drop-off and the like.

The term “waste” is intended to mean mixed solid waste (domestic, residential or commercial), such as plastics, paper, cardboard, textiles, foods, etc. The waste may also contain glass and metals, however they will not be altered by the pyrolysis reaction. Preferably, the wastes is composed of mixed plastics or other non-recyclable wastes such as food and any of the non-recycled plastics, paper, cardboard, textiles.

The term “char” or “carbonaceous by-product” is intended to mean the char used as an embedded heater in the process of the present invention, a hot catalyst phase used in the process of the present invention, as well as a self-generated product of the process of the present invention. This “carbonaceous by-product” or “char” may be composed of over 80% carbon.

The expression “small-scale” or “small to medium-scale” is intended to mean from about 0 to about 250 Kg of waste per batch, and preferably, the average weight of a waste disposal bag.

The term “open batch” is intended to mean that the batch system will have an outlet open to the outside of the reactor throughout the process to avoid pressure build-up and to collect the liquid and gas product.

The term “pyrolysis” is intended to mean the chemical decomposition of condensed substances by heating that occurs spontaneously at high enough temperatures in absence of oxygen. The word is coined from the Greek-derived elements pyro “fire” and lysys “decomposition”.

The term “microwave” is intended to mean electromagnetic waves with wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz (0.3 GHz) and 300 GHz. Preferably, the range of microwaves suitable to be used in the present invention is from about 915 MHz to about 2450 MHz.

Features and advantages of the subject matter hereof will become more apparent in light of the following detailed description of selected embodiments, as illustrated in the accompanying figures. As will be realized, the subject matter disclosed and claimed is capable of modifications in various respects, all without departing from the scope of the claims. Accordingly, the drawings and the description are to be regarded as illustrative in nature, and not as restrictive and the full scope of the subject matter is set forth in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which:

FIG. 1 illustrates an example of a conventional approach to waste management. Community may be formed by individuals or commercial entities.

FIG. 2 illustrates an example of a method of producing pyrolysis by-products according to the present invention.

FIGS. 3A and 3B illustrate system for performing small scale pyrolysis in a distributed way and creating value through at least one pyrolysis by-product produced according to embodiments of the present invention.

It will be noted that throughout the appended drawings, like features are identified by like reference numerals.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will reduce the volume of waste at the source by at least 90%, which will reduce transportation, collection and disposal costs of waste that represent from about 60% to about 70% of the total expenditures related to current waste management strategies. Also, the present invention also results in the production of energetic by-products that may be sold and used or even reused on site.

According to an embodiment of the present invention, the pyrolysis apparatus that is proposed for use in the method of the present invention is designed to maximize the production pyrolytic oils (or bio-oils) over gases since pyrolytic oil valorization offers more economical opportunities such as fuel for transportation, base for the production of industrial chemicals, etc. In contrast, pyrolysis gases involve major technical difficulties related to transportation, storage and utilization. Pyrolysis that favors the production of pyrolytic oils (or bio-oils) is also referred to as “fast pyrolysis”. In a preferred embodiment, the type of pyrolysis performed by the apparatus in the present invention is a “fast pyrolysis”.

According to another embodiment, the any suitable pyrolysis apparatus may be employed in the method of the present invention. In a preferred embodiment, the pyrolysis apparatus is a microwave pyrolysis apparatus.

Electrical power easily allows for the efficient production of microwaves, an energy source that can efficiently transform biomass and waste into pyrolytic oils (bio-oils), gas (bio-gas) and carbon black (char, or bio-char). Moreover, the use of electrically powered microwaves for pyrolysis combined with an appropriate catalyst requires less energy per unit mass of waste treated compared to traditional surface-based heating approaches. Also, the technology is energy positive. Despite the need for electricity for the generation of the microwaves, if the pyrolytic gas generated is used to replace electricity as an energy sources for certain domestic applications (such as domestic or hot water heating), then the system also contributes to increasing the overall energy efficiency by keeping a noble energy (electricity) for applications other than heating. Microwave heating has also been proven to be safe since ovens are already present in many households.

The pyrolysis process in accordance with one embodiment is entirely based on microwave pyrolysis such that heat is provided through absorption of microwaves by a catalyst and by the media itself. It is a batch operated process that subjects domestic waste to a complete pyrolysis reaction. Addition of a carbon-based catalyst is required to absorb microwaves and transfer heat to the microwave-transparent waste which initiates the pyrolysis reaction.

According to one embodiment of the present invention, the pyrolysis process is for small to medium scale waste quantities. For example, the process is for pyrolysis of about 0 kg to about 250 kg of waste, or for about less than 250 kg, or for about less than 40 kg, or about less than 20 kg, or about less than 10 kg, or about less than 8 kg, or about less than 5 kg. According to one embodiment, the process is for pyrolysis of about 1 kg to about 20 kg, or from about 1 kg to about 20, kg, or from about 1 kg to about 10 kg, or from about 1 kg to about 8 kg, or from about 1 to about 5 kg. Preferably, the process is for pyrolysis of an average domestic waste containing bag. The waste may be any domestic, residential or commercial waste, such as plastics, paper, cardboard, textiles, foods, etc, and also include glass and metals. However glass and metals will not be altered by the pyrolysis reaction. Preferably, the wastes are non-recyclable wastes such as food and any of the non-recyclable or reusable plastics, paper, cardboard, textiles. According to the method of the present invention, no waste would be transported off the premise of the production site intact, but would rather be transformed to energetic by-products.

Distribution of Pyrolysis by-Products

In embodiments there is disclosed a method of distributing pyrolysis by-products comprising the step of distributing at least one pyrolysis by-product obtained from a production site to at least one by-product processor. The pyrolysis by-products are produced by small scale pyrolysis of a waste at the production site, in a decentralized manner.

According to an embodiment of the present invention, the method may further comprise providing a pyrolysis apparatus to the production site. In this manner production sites, such as houses, restaurants, hotels, small, medium or large companies, commercial airlines etc, all of which are together responsible for a large percentage of the world's MSW, may form a plurality of production sites whose combined pyrolysis by-products form a plurality of pyrolysis by-products. According to an embodiment, the apparatus may be leased, sold or put in consignment at the production site.

According to another embodiment, the lease of the pyrolysis apparatus may be charged to an operator of the production site (i.e., providing cost avoidance for the operator of the production site). For example, leasing costs may be charged monthly, annually or daily to the operator of the production site.

According to another embodiment, a profit may be shared (i.e., based on the grade and/or volume of pyrolysis by-products such as oil generated from the feedstock) with the leaser (i.e., the operator of the pyrolysis apparatus).

According to another embodiment, the method provides a cost reduction by avoiding landfilling matter (i.e., hauling costs, landfill costs, environmental taxes and the like).

According to another embodiment of the present invention, the pyrolysis apparatus may comprises a monitoring system to provide a status of the pyrolysis apparatus. The apparatus may report statuses which include apparatus malfunction, maintenance requirement, and by-product level status. The apparatus may communicate the status to an external recipient, such as the user of the apparatus, or an integrator who will take the necessary action. The status may be communicated by any suitable means, such as with a display on the apparatus, or remotely through the internet, cellular network, and the likes.

Furthermore, according to another embodiment, the pyrolysis apparatus may be provided with an appropriate encryption key to allow operation at the production site. The encryption key may be provided through any suitable means, for example, by mail or telephone, or remotely through connection to a internet or cellular network which will provide the appropriate encryption key to allow operation at the production site. This aspect ensures, for example, that the operator is an authorized user and has paid all due fees and charges related the equipment and that he is following the rules set by the contract.

According to an embodiment, the method may further comprise collecting the at least one pyrolysis by-product from the production sites before distribution to by-product processors. Examples of by-product processors include but are not limited to energy companies, oil companies, gasoline (fuel) companies, gas company, a construction material companies, tire companies, chemical companies, rubber companies, or combinations thereof.

According to an embodiment, prior to distribution, the pyrolysis by-products may be received by an integrator at a single location point, which may perform some transformation on the pyrolysis by-product. For example, the integrator may upgrade the bio-oil by-product, transform or purify the bio-char (metal removal, homogenization and sterilization through heat treatment, activation of carbon), as well as package and ship of the products for distribution to the by-product processor.

The selected integrators or processors may also be responsible for coordinating collection of the pyrolysis by-product, maintain and upgrade the pyrolysis apparatus, as well as replace disposable supplies (such as disposable filters, powder collection bags, oil containers, etc.).

Embodiments of the present invention, allow for the following advantages:

Reducing the volume of energy consumption for collection. 7 to 15 liters of fuel are required for each ton of waste. The present invention will reduce the volume of waste to be collected by at least 90%, thus reducing total greenhouse gas (GHG) emissions.

Reducing the volume of buried waste. Decay produces gaseous chemical with significantly higher global warming potential compared to carbon dioxide (for example, methane has a greenhouse factor 27 times higher than carbon dioxide in trap-ping heat in the atmosphere).

Producing pyrolysis gases, oils and carbon black from wastes for use in energy (electricity & heat generation) and transport applications. These pyrolysis by-products are biogenic and by replacing traditional fossil fuels, they will contribute to reduce GHG emissions and reduce pressure on current deposits.

The pyrolysis of waste and purification of the products will also minimize the emissions of sulphur compounds (sulphur oxides) and other pollutants (particulate matter, ash). Furthermore, reducing the volume of waste for burial will reduce the impacts of landfills on land and water contamination.

Pyrolysis/gasification of MSW with conventional technology has shown to be unefficient at large scale (10 tons/day and more) due to scale-up difficulties and long term operation problems and especially problems related to heat transfer. Microwave heating, although not sensitive to fouling compared to other conventional heating approaches, can be hardly applied to large scale unit. Therefore, this makes the pyrolysis apparatus unit used in the present invention unique and energetically efficient.

Large pyrolysis plants are centralized and require additional costs to carry the required flow of feedstock to the plant: it has a negative impact on the environment and profitability of the current business. The approach of the method of the present being distributed, it allows for a significant cost reduction related to transportation and collection of waste. A plurality of pyrolysis apparatus are installed at a plurality of sites and each contribute to the production of by-product in a distributed and decentralized manner.

Batch small scale microwave-assisted pyrolysis represents a true technological break-through because it minimizes issues related to conventional processes. However, it is difficult to implement within large-scale processes and this is why it is particularly suitable for a small scale or small to medium scale pyrolysis unit. Compared to conventional heating, microwave heating offers several operational advantages:

Small scale (or small to medium scale) pyrolysis offers multiple advantages that are not there with large scale pyrolysis/gasification processes such as: no minimum volume required, reduction of waste volume at the source which reduces the transportation and collection costs of wastes, the possibility to burn the clean gas produced at the source for other applications (water heating, replacing heating fuel). Less sensitive to fouling: reactor walls and other components are not used for heating which reduces the sensitivity to fouling. Increased heat transfer efficiency: ashes, carbon black and moisture promote heat generation under the action of microwaves, thereby reducing the time required to heat the biomass. Improved control of reaction time: a shorter pyrolysis time maximizes the production of oils over gases and allows for improved control of oil composition.

Improved energy efficiency: power consumption during the pyrolysis process is significantly lower compared to conventional pyrolysis. Increased efficiencies emanate from: (i) reactor walls that are not heated and (ii) the above described elements. However, an overall energy balance including electric power generation may reveal that conventional heating is more cost-effective. In fact, if electricity is produced by a thermal plant (gas turbine, pulverized coal fired station, etc.), the microwave energy performance could be lower due to the second principal of thermodynamics. However, in countries where electricity generation is essentially hydraulic and wind-based (such as Canada), microwave heating may be more efficient.

Batch pyrolysis of biomass and waste offers several advantages over continuous processes, in particular with respect to the separation of water from bio-oil. In a batch process, it is possible to perform torrefaction of the bio-mass/waste prior to pyrolysis which improves substantially the quality of the bio-oil. With the appropriate catalysts, it is also possible to further improve the hydrocarbon content of the oil and improve the quality and stability of the bio-oil.

FIG. 1 illustrates a conventional approach to waste management. Communities may be formed by individuals or commercial entities. The waste selection criterions are that it is available and accessible, homogenous, in important volumes and concentrations, and only a low amount is diverted.

FIG. 2 illustrates an approach to waste management according to the present invention which includes no minimum volumes to operate the pyrolysis unit, which may or may not include the use of the produced bio-gas for heating (for example hot water, home heating, and stove). According to an embodiment, clean metal and glass residues that are left behind after the pyrolysis are separated from char and diverted through conventional recycling routes. According to an embodiment (e.g. FIG. 2), the pyrolysis by-products may be collected on-demand, to allow using optimal paths or routes, and minimum energy for collection. According to another embodiment, collection may be performed according to a predetermined schedule. According to yet another embodiment, performed according to a level of the pyrolysis by-products at the production sites.

According to one embodiment, the volume of the by-products represents about 1% to about 5% of the original waste volume. The valorization of the by-products produced by the pyrolysis apparatus used in the method of the present invention represent a perpetual source of revenue, as MSW are continuously produced at the production sites and collected for sale. Additional revenues are generated by the payment of fees for collection of the by-products as well as rental as well as maintenance of the pyrolysis apparatus.

The Pyrolysis gas

The pyrolysis gas or bio-gas represents about 13%-20% of the waste mass which ends up in bio-gas containing mostly hydrogen and methane. Pyrolysis produces a high quality gas with high calorific values. Most of its constituents are presented in Table 1.

TABLE 1 Main constituents in pyrolysis gas Vol fraction (%) n-C₅H₁₂ 0.59 i-C₅H₁₂ 1.83 cis-C₄H₈ 0.04 trans C₄-H₈ 0.21 n-C₄H₁₀ 0.31 i-C₄H₁₀ 2.16 C₃H₈ 0.87 C₃H₆ 2.29 H₂S 0.20 C₂H₆ 2.73 CO₂ 6.82 CH₄ 10.76 H₂ 61.72 CO 1.15 Others 8.34

The average heating value of this bio-gas is nearly 40 MJ/kg, which is about 80% that of natural gas. On a volumetric basis, the gas has a heating value of 23 000 kJ/m³, which is about 60% that of natural gas.

According to the U.S. Energy Information Administration, restaurants that use natural gas use the majority for cooking load (45%), then space heating (27%), and finally water heating (28%). According to various sources, a fast-food restaurants use a yearly average of 536 therms/employees in natural gas. An average location operates with 13.4 employees which make them require around 7190 therms/year or 210 MWh/year of natural gas.

Typical yields from the method of the present invention are in the range of 10%-20% of bio-gas which accounts to the production of an average of 30 to 60 MWh/year of energy. The upper range covers most of the natural gas needs for water heating of a conventional fast food establishment (60 MWh/year for water heating). Aware of the fact that hot water might not be used on a continuous basis, alternatively the pyrolysis gas could be used to supply between 14% and 27% of the total natural gas needs. Appropriate adapters on existing burners are required and may be supplied to allow the use of this highly energetic gas.

The average annual savings per restaurant assuming a cost of 8$/GJ of natural gas would be around $1,700 for a fraction of gas produced of 20%.

The pyrolysis apparatus may be equipped to collect the bio-gas for later collection. Alternatively and preferably, tools and engineered solution packages for the conversion of home electrical appliances, such as water heaters, stove, ovens, refrigerators, heating systems into gas fuelled systems are provided to directly use the bio-gas. Waste conversion produces gas with more energy per kg than natural gas, which makes it suitable for co-generation. This would yield savings on electricity bills and also further alleviate the carbon footprint in areas where electricity is mainly produced by burning fossil fuels.

The Bio-Oil

From about 50% to about 75% of the waste may be converted in liquid containing various fractions of hydrocarbons, oxygenated compounds and amides (depending on the waste composition). According to an embodiment, the bio-oil may be refined and treated to naphta and diesel grade.

Biomass energy consumption is projected to increase by 4.4% per year from 2007 to 2030 compared to 0.5% increase in primary energy consumption for end-use markets. By 2030, biomass consumption in primary markets is expected to reach 20% of renewable energy sources. Although ethanol and biodiesel have led the adoption of renewable fuels in the transportation industry, the Energy Independence and Security Act of 2007 mandates production of at least 36 billion gallons of renewable fuels by 2022 with cellulosic biofuels contributing more (16 billion gallons) than corn ethanol (15 billion gallons).

Production of bio-oil from fast pyrolysis brings several technological limitations. In fact, most of the biomass contains sugars, mainly cellulose and hemicellulose. This is particularly true for paper, wood and other cellulosic (or fibrous) materials such as fruits and vegetables and cereals. The bio-oil obtained from pyrolysis of cellulosic material is known to contain high levels of oxygenated compounds and acids, such as furfural and acetic acids. Presence of these compounds decrease the energetic value of the bio-oil and requires a catalytic upgrading step to improve the quality of the oil and increase fraction of aromatics and hydrocarbons.

Other types of waste like plastics, oil and lipids contain mainly hydrogenated hydrocarbons and pyrolysis of such waste is not known to yield significant issues with the bio-oil. In fact, bio-oil obtained from pyrolysis of scrap tires is known to be usable with no further upgrading.

Domestic waste also contains proteins from food residues. Proteins contain quite a large amount of nitrogen and sulfur which may have a negative impact on the quality of the bio-oil especially because of the presence of highly reactive oxygenated functionalities in the oil. This is known to be due to the reaction between amides from protein degradation and oxygenated compounds from the decomposition of polysaccharides and lignin.

Oil upgrading and conversion to diesel: Bio-oil upgrading is a catalytic conversion technology that can contribute to renewable fuels by producing naphtha and diesel range stock fuel starting from highly oxygenated bio-oils. Most of the issues start with the high water content around 15%-30% found in the conventional pyrolysis oil (PO). Preferably, the oil obtained from method of the present invention will contain rather small amount of water, in the range below 5% by using a process which involves a torrefaction step which removes the water from the biomass prior to the pyrolysis.

Several studies have shown the feasibility of converting bio-oil obtained from bio-mass into diesel and gasoline. Little fraction of water in the oil will contribute to make the conversion through hydrotreating easier. However, typical yields of diesel and gasoline over bio-oil containing high fractions of water are around 30% to 50% of the incoming feed. It mainly depends on how hydrogen is fed to the process, either by cracking some of the oil (hydrogen production) or by purchasing hydrogen. Production of hydrogen reduces the yield because it breaks down some of the “good” molecules to liberate hydrogen used for upgrading the “bad” molecules (mainly oxygenates, unsaturated, sulfides, etc) to produce good diesel. According to one embodiment of the present invention, the bio-oil may be upgraded at the source. According to another embodiment, the bio-oil may be upgraded at a later stage, by the by-product processor.

Advantages of the bio-oil produced by the method of the present invention over other bio-oils.

The approach proposed of the present invention is somewhat different and involves less capital expenditure to perform bio-oil upgrading due to its distributive processing. Where it is estimated that a 2000 ton/day corn stover pyrolysis plant costs around 200 M$, about 26% of this cost is related to equipment for pyrolysis itself and roughly 40% to combustion of the char to provide heat for drying the incoming biomass.

In the large scale pyrolysis plants, analysis show that from conventional biomass (wood chips, corn stover etc), the biomass costs represents between 60% and 80% of the total operational cost. Biomass is expensive as opposed to waste.

According to an embodiment, the approach of the present invention has the advantage of dealing with a distributed pyrolysis system where small scale pyrolysis systems produce the heavy oil which is further collected and refined through hydroprocessing. The advantages are:

a) Minimum capital cost since required by the small scale units;

The small scale allows for a better control of the catalysts to upgrade as much of the oil at the source;

b) The incoming feedstock in the upgrading plant is a liquid which is more convenient to manipulate, as opposed to conventional plants starting with biomass directly;

c) The microwave pyrolysis process already separates the water from the bio-oil which avoids the need for a complex drying system and further improves the quality of the bio-oil;

d) The waste is free, and thus leaves room for more profitability when producing bio-fuels from waste pyrolysis oil as opposed to using pyrolysis oil obtained from biomass.

The Bio-Char

The char or bio-char represent about 12% of the total waste remains as carbonaceous material. It also contains minerals (ash) and other impurities. According to an embodiment, bio-char may be used as an additive in cement, or further transformed for the production of carbonaceous compounds, such as activated carbon, and the likes.

The global demand for char is expected to climb by 2% per year to 11.7 M tons in 2015.

Price of carbon black ASTM N550 varied between 0.73 $/kg (1998) and 0.95 $/kg (2001). Around 70% of the carbon black is used for fabrication of tires, 11% for chemicals, 10% for the car industry and 9% for industrial rubber products.

The challenges with the char is mostly due to the presence of heavy metals and other contaminants such as sulphur, iron, zinc, arsenic. Several alternatives to valorize this residue are considered with increasing levels of difficulties.

Gasification or Incineration of Char

According to one embodiment of the present invention, the bio-char from pyrolysis can be gasified or incinerated. This process has been applied to char produced through medium temperature pyrolysis of municipal waste, electronic scrap, wood and straw. Typical char obtained after pyrolysis of municipal wastes at 500° C. shows presence of several metals. As a basis of comparison, ashes from incinerated waste contains metals as well where most commonly found are Cr, Cu, Hg, Ni, Cd, Zn and Pb with Zn and Pb usually in the largest amount. These metals may cause leaching problems and are harmful to the environment without proper treatment. Generally, the heavy metal content in fly ash is higher than in bottom ash due to the vaporization of metals during combustion and the process of metals adsorption on the surface of fly ash particles. Municipal Solid Waste Incinerator (MSWI) fly ash contains a much higher chloride content than MSWI bottom ash. This may be due to the lime scrubber in the air pollution control system, which removes acidic gases such as HCl, thus resulting in a high amount of chloride content remaining in fly ash after the air pollution control system.

The ashes obtained from the gasification of waste char can be used in various applications:

-   -   Bottom ashes: uses as aggregate in concrete (up to 50%), road         base, adsorbent for dyes.     -   Mixed ashes: Several uses in cement clinker (between 1.75% to         50%). Applications in Portugal, Japan and Taiwan.     -   Fly ashes: uses in concrete (France), eco-cement (Japan),         ceramic tiles (China), glass ceramic (Korea), cement clinker         (China) and blended cement (UK).

Bio-Char Purification Processes

Among the existing processes, leaching aims to extract the heavy metals from bio-char and to further recover them from the leachant solutions. In order to recover the heavy metals, their concentration must be high to ensure recovery. The leaching of heavy metals depends on the type of extraction solvent, the pH, as well as the liquid-to-solid ratio.

An electrochemical route also exists where the objective of the process is to remove heavy metals and further recover them. The process involves the application of an electric potential to force the reduction/oxidation reactions on the surface of the cathode and anode. During the process, metals are deposited on the surface of cathode. Although the processes do not involve chemical addition, the efficiencies are quite low.

Portability

According to an embodiment of the present invention, as the method of the present invention employs a pyrolysis apparatus that is of a relatively modest, appliance size (e.g. similar to a refrigerator, freezer, or the like). The method of the present invention may be easily portable to installations, from one site to another, or even to remote area such as mining or prospecting camps where waste disposal in order to limit the environmental footprint of the activity represents a significant challenge. Waste matter which would normally be burnt or transported off site to more industrialized areas for treatment can be transformed into useful energetic material which may be directly used on site or, when transported off site is reduced to one tenth of the original volume of the waste material.

The apparatus used in the present invention represent a sizable advantage over usual pyrolysis equipment which tends to require an entire building. Moreover, several apparatuses of the present invention may be employed in industrial settings. For example, in large industries, they may be disposed in several locations within the facility in locations normally occupied by common appliances, freeing space that a centralized waste disposal and treatment area would normally occupy.

System for Performing Small Scale Pyrolysis

Now referring to FIGS. 3A and 3B, in embodiments there is disclosed a system 10 for performing small scale pyrolysis in a distributed way and creating value through at least one pyrolysis by-product produced. The system comprises a pyrolysis apparatus 14, for small scale pyrolysis of at least one waste at the production site 12. The system also comprises a transport apparatus 16 for transportation of the pyrolysis by-products to at least one by-product processor 18. According to an embodiment, the transport apparatus may be a motorized vehicle (non limiting examples include trucks, wagons, or cars), piping, such as underground piping laid between the production site and the by-product processor. The transport apparatus may also be combinations of vehicular transportation and piping. For example, piping could transport the by-products up to a storage station connecting several productions sites (e.g. several residential homes) and a truck could come and collect the accumulated by-products at this site.

According to another embodiment, apparatus 14 for small scale pyrolysis may be leased, or sold, to the production site 12, in consignment at the production site 12, or even transported to said production site 12 for on-site pyrolysis of the waste. The last option makes use of the portable nature of the pyrolysis apparatus used in the present system, by transporting the apparatus from one production site 12 to another when these sites, for example, do not wish or cannot maintain an apparatus 14 at the production site.

According to another embodiment, the by-product processor 18 may be at the production site 12. For example, as illustrated in FIG. 3B, the by-products produced by the pyrolysis apparatus 14 are transported through transport apparatus 16 (e.g. a piping system) to the by-product processor 18 which is located at the production site 12.

According to another embodiment, the system may further comprise an integrator 20 for receiving the by-products prior to transportation to the by-product processor 18. For example, and as illustrated in FIG. 3A, the by-products may be transported by transport apparatus 16 to the integrator 20, which perform some transformation on the by-products as described above, package and ship the by-products to the by-product processor 18.

According to another embodiment, the system may further comprise a monitoring system 30, which may provide the status of the pyrolysis apparatus 14. According to another embodiment, The system may report statuses which include apparatus malfunction, maintenance requirement, and by-product level status. The apparatus may communicate the status to an external recipient, such as the user of the apparatus, or an integrator who will take the necessary action. The status may be communicated by any suitable means, such as with a display on the apparatus, or remotely through the internet, cellular network, and the likes.

Furthermore, according to another embodiment, the system 30 may be provided with an appropriate encryption key to allow operation at the production site 12. The encryption key may be provided through any suitable means, for example, by mail or telephone, or remotely through connection to a internet or cellular network which will provide the appropriate encryption key to allow operation at the production site. This aspect ensures, for example, that the operator is an authorized user and has paid all due fees and charges related the equipment and that he is following the rules set by the contract.

According to embodiments of the present invention, by-product processors 18 include but are not limited to energy companies, oil companies, gasoline (fuel) companies, gas company, a construction material companies, tire companies, chemical companies, rubber companies, or combinations thereof. According to embodiments of the present invention, production sites 12 may be a house, a restaurant, an office building, a hotel, an airport, a waste treatment plant of an airline, a recycler's site, a sorting facility, a recycling material drop-off and the like.

While preferred embodiments have been described above and illustrated in the accompanying drawings, it will be evident to those skilled in the art that modifications may be made without departing from this disclosure. Such modifications are considered as possible variants comprised in the scope of the disclosure. 

1. A method of performing small scale pyrolysis in a distributed way and creating value through at least one pyrolysis by-product produced therefrom which comprises: a) producing at least one pyrolysis by-product by small scale pyrolysis of at least one waste at a production site to be used by at least one by-product processor.
 2. The method according to claim 1, further comprising the step a′) prior to step a): a′) operating an apparatus for small scale pyrolysis of said waste at a production site.
 3. The method according to any one of claims 1-2, further comprising step b) after step a): b) collecting said at least one pyrolysis by-product from said production sites.
 4. The method according to any one of claims 1-3, wherein said by-product processor is at said production site.
 5. The method according to any one of claims 2-3, wherein said apparatus for small scale pyrolysis is leased to said production site, sold to said production site, in consignment at said production site, or transported to said production site.
 6. The method according to claim 3, wherein said at least one pyrolysis by-product is received by an integrator prior to distribution to said at least one by-product processor.
 7. The method according to claim 3, wherein a glass residue, a metal residue, or both produced by said small scale pyrolysis of at least one waste is recycled.
 8. The method according to any one of claims 2-7, wherein operating said apparatus for small scale pyrolysis is performed by at least one of an owner of said production site, an owner of said apparatus, a producer of said apparatus, a purchaser of said apparatus, said by-product processor, said integrator, a third party operator of said apparatus, a lender of said apparatus, a seller of said apparatus, a leaser of said apparatus, a leaseholder of said apparatus, a transporter of said apparatus, or combinations thereof.
 9. The method according to any one of claims 1-8, wherein said apparatus for small scale pyrolysis is a portable apparatus.
 10. The method according to any one of claims 1-9, wherein said at least one pyrolysis by-product is chosen from a bio-char, a bio-gas, a bio-oil, and combinations thereof.
 11. The method according to claim 10, further comprising the step of using said bio-gas, said bio-oil and/or said bio-char on-site at said production site.
 12. The method according to claim 11, wherein said bio-gas is used for heating, water heating, or cooking.
 13. The method according to claim 12, wherein said bio-gas is used at said production site.
 14. The method according to claim 12, wherein said bio-gas is mixed with at least one other source of gas.
 15. The method according to claim 12, wherein said bio-gas is used by at least one of said owner of said production site, said owner of said apparatus, said producer of said apparatus, said purchaser of said apparatus, said by-product processor, said integrator, said third party operator of said apparatus, said lender of said apparatus, said seller of said apparatus, said leaser of said apparatus, said leaseholder of said apparatus, said transporter of said apparatus, or combinations thereof.
 16. The method according to any one of claims 3-7, wherein said collecting of said at least one pyrolysis by-product is performed on-demand.
 17. The method according to any one of claims 3-7, wherein said collecting of said at least one pyrolysis by-product is performed according to a predetermined schedule.
 18. The method according to any one of claims 3-7, wherein said collecting of said at least one pyrolysis by-product is performed according to a level of said pyrolysis by-products at said production site.
 19. The method according to any one of claims 2-18, wherein said pyrolysis apparatus further comprises a monitoring system to provide a status of said pyrolysis apparatus.
 20. The method according to claim 19, wherein said status comprises at least one of an apparatus malfunction, a maintenance requirement, and a by-product level status.
 21. The method according to any one of claims 2-20, wherein said pyrolysis apparatus is provided with an encryption key.
 22. The method according to claim 21, wherein said encryption key is to authorize operation of said pyrolysis apparatus at said production site.
 23. The method according to any one of claims 1-22, wherein said pyrolysis is a fast pyrolysis.
 24. The method according to any one of claims 1-23, wherein said pyrolysis is a microwave pyrolysis.
 25. The method according to any one of claims 1-24, wherein said pyrolysis further includes a torrefaction step for removing water from said at least one waste.
 26. The method according to any one of claims 7-25, further comprising the step of upgrading said bio-oil.
 27. The method according to claim 26, wherein said upgrading is performed at said production sites, by said integrator, by said by-product processor, or combinations thereof.
 28. The method according to any one of claims 7-26, further comprising the step of purifying said bio-char.
 29. The method according to claim 28, wherein said step of purifying said bio-char includes removal of metals, homogenization and sterilization, activation of carbon, and combinations thereof.
 30. The method according to any one of claims 1-28, wherein said by-product processor is chosen from a energy company, an oil company, a gasoline company, a gas company, a construction material company, an agricultural company or combinations thereof.
 31. The method according to any one of claims 1-30, wherein said production site is at least one of a house, a restaurant, an office building, a hotel, an airport, a waste treatment plant of an airline, a recycler's site, a sorting facility, and a recycling material drop-off.
 32. A system for performing small scale pyrolysis in a distributed way and creating value through at least one pyrolysis by-product produced therefrom which comprises: a pyrolysis apparatus for small scale pyrolysis of at least one waste at a production site, and a transport apparatus for transportation of said at least one pyrolysis by-product to at least one by-product processor.
 33. The system according to claim 32, wherein said transport apparatus is at least one of a motorized vehicle, a piping, or combinations thereof.
 34. The system according to any one of claims 32-33, wherein said apparatus for small scale pyrolysis is leased to said production site, sold to said production site, in consignment at said production site, or transported to said production site.
 35. The system according to any one of claims 32-34, wherein said by-product processor is at said production site.
 36. The system according to any one of claims 32-35, further comprising an integrator for receiving said at least one by-product prior to transportation to said by-product processor.
 37. The system according to any one of claims 32-36, wherein said apparatus for small scale pyrolysis is a portable apparatus.
 38. The system according to any one of claims 32-37, further comprising a monitoring system to provide a status of said pyrolysis apparatus.
 39. The system according to claim 38, wherein said status comprises at least one of an apparatus malfunction, a maintenance requirement, a by-product level status, an authorized operation status and combinations thereof.
 40. The system according to any one of claims 32-39, wherein said pyrolysis apparatus is provided with an encryption key.
 41. The system according to claim 40, wherein said encryption key is to authorize operation of said pyrolysis apparatus at said production site.
 42. The system according to any one of claims 32-41, wherein said by-product processor is chosen from a energy company, an oil company, a gasoline company, a gas company, a construction material company, an agricultural company or combinations thereof.
 43. The system according to any one of claims 32-42, wherein said production site is at least one of a house, a restaurant, an office building, a hotel, an airport, a waste treatment plant of an airline, a recycler's site, a sorting facility, and a recycling material drop-off. 